title: Preoperative venous intimal hyperplasia, postoperative arteriovenous fistula stenosis, and clinical fistula outcomes.
abstract: OBJECTIVE
  Arteriovenous fistulas often fail to mature, and nonmaturation has been attributed to postoperative stenosis caused by aggressive neointimal hyperplasia. Preexisting intimal hyperplasia in the native veins of uremic patients may predispose to postoperative arteriovenous fistula stenosis and arteriovenous fistula nonmaturation.
  
  
  METHODS
  This work explored the relationship between preexisting venous intimal hyperplasia, postoperative arteriovenous fistula stenosis, and clinical arteriovenous fistula outcomes in 145 patients. Venous specimens obtained during arteriovenous fistula creation were quantified for maximal intimal thickness (median thickness=22.3 μm). Postoperative ultrasounds at 4-6 weeks were evaluated for arteriovenous fistula stenosis. Arteriovenous fistula maturation within 6 months of creation was determined clinically.
  
  
  RESULTS
  Postoperative arteriovenous fistula stenosis was equally frequent in patients with preexisting venous intimal hyperplasia (thickness>22.3 μm) and patients without hyperplasia (46% versus 53%; P=0.49). Arteriovenous fistula nonmaturation occurred in 30% of patients with postoperative stenosis versus 7% of those patients without stenosis (hazard ratio, 4.33; 95% confidence interval, 1.55 to 12.06; P=0.001). The annual frequency of interventions to maintain arteriovenous fistula patency for dialysis after maturation was higher in patients with postoperative stenosis than patients without stenosis (0.83 [95% confidence interval, 0.58 to 1.14] versus 0.42 [95% confidence interval, 0.28 to 0.62]; P=0.008).
  
  
  CONCLUSIONS
  Preexisting venous intimal hyperplasia does not predispose to postoperative arteriovenous fistula stenosis. Postoperative arteriovenous fistula stenosis is associated with a higher arteriovenous fistula nonmaturation rate. Arteriovenous fistulas with hemodynamically significant stenosis frequently mature without an intervention. Postoperative arteriovenous fistula stenosis is associated with an increased frequency of interventions to maintain long-term arteriovenous fistula patency after maturation.
authors.affiliation: Divisions of Nephrology and, ‡Transplant Surgery and, Departments of †Radiology and, §Pathology, University of Alabama, Birmingham, Alabama.
authors.forename: Michael
authors.initials: M
authors.lastname: Allon
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Robbin
authors.forename: Carlton J
authors.initials: CJ
authors.lastname: Young
authors.forename: Mark H
authors.initials: MH
authors.lastname: Deierhoi
authors.forename: Jeremy
authors.initials: J
authors.lastname: Goodman
authors.forename: Michael
authors.initials: M
authors.lastname: Hanaway
authors.forename: Mark E
authors.initials: ME
authors.lastname: Lockhart
authors.forename: Silvio
authors.initials: S
authors.lastname: Litovsky
mesh_terms: D000328:Adult; D000368:Aged; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects*; D003251:Constriction, Pathologic / Q000209:etiology; D005260:Female; D006801:Humans; D006965:Hyperplasia; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome; D017539:Tunica Intima / Q000473:pathology*